No abstract

Broiler chicken genetics, gompertz, viscera yield.

This experiment was carried out to study the effect of dietary exogenous monocomponent protease on the coefficient apparent total tract (ATTD) and apparent ileal (AID) digestibility of amino acids of corn, soybean meal (SBM) and full fat soybean meal (FFSM) in broilers. A total of 400 males Cobb-500 (14 days of age) were equally allocated in 80 metabolic cages (50 x 50 x 45 cm) in a completely randomized design and a semi-controlled environment. Eight treatments (basal diet with or without a protease and three ingredients replacing the basal diets in 40 % to corn and 30 % to SBM and FFSM, with and without protease), with 10 replicates each were evaluated. The protease was added at 200 mg/kg resulting in 15,000 unit of PROT/kg .The total collection of excreta was held during three days, after five days for adaptation of broilers at the diets. The ileal content was collected on day 21, after slaughter of birds. The enzyme increased (P < 0.05) the ATTD and AID of most amino acids contained in SBM and FFSM. The digestibility of cysteine, glycine, proline and threonine had higher (P<0.05) ATTD and AID in all tested ingredients with the use of protease. On average, the dietary protease increased in 5.19 % and 3.86 % the total and ileal digestibility of amino acids, respectively. It was concluded that the dietary protease exerts major effects on toasted full-fat soybean, followed by soybean meal and corn to broilers.

A digestibility experiment was conducted to evaluate the effects of dietary exogenous monocomponent protease on the coefficient of apparent total tract digestibility (ATTD) and coefficient apparent ileal digestibility (AID) of amino acids in meat and bone meal (MBM), poultry by-products meal (PBPM), and feather meal (FM). A total of 512 Cobb-500 male broiler chickens (aged 14 d) were randomly placed into 64 metabolism cages (8 birds/pen) and were allocated to eight treatments with eight replicates in a semi-controlled environmental room. The experimental diets consisted of the basal diet (corn/SBM) and the replacement of 300 g/kg on a weight basis with MBM, PBPM or FM. The excreta were collected during three days (19 to 21 d), and the ileal digesta (using Celite TM as an indigestible marker) only one day (21 d). The protease contained 75,000 PROT units/g. The use of the enzyme increased (P < 0.05) ATTD for alanine, cysteine, glycine, and threonine in the basal diet and AID for the amino acids alanine, cysteine, glycine, lysine, threonine, and valine for the basal diet (vegetable). Regarding meals, there was an increase (P < 0.05) in the amino acid digestibility in large part due to the amino acids of MBM (14) and PBPM (9), with only five amino acids for FM. The amino acids glycine and threonine showed increases (P < 0.05) in both total and ileal digestibility for all animal meals and for the diet based on corn and soybean meal, which indicates a high specificity of the enzyme for these amino acids. The overall results obtained in this study found satisfactory effectiveness of this exogenous protease. The total collection method was lower by 1.83% of amino acids digestibility than the ileal method.

No abstract

The objective of this work was to evaluate performance parameters, carcass and cut yields, meat quality, plasma glutathione peroxidase (GSH-Px) activity, and selenium tissue deposition for broilers fed with Se from organic (Se-yeast) and inorganic (sodium selenite) sources. A total of 1,200 Cobb 500 chicks, males with one day of age, were randomly distributed into four treatments with ten replicates. The treatments consisted of two Se-yeast levels (3,000 and 2,000 ppm), sodium selenite (45.7%), and the combination between sodium selenite and 3,000 ppm Se-yeast. All diets, based on corn and soybean meal, were supplemented with 0.3 ppm Se. Among treatments, there were no differences for performance, carcass and cut yields, and meat quality. Diets containing only Se-yeast provided meat with lower values of thiobarbituric acid reactive substances. A higher GSH-Px activity was observed with 3,000 ppm Se-yeast and a greater deposition of Se in the muscle tissue with Se-yeast. The sources of Se do not affect performance parameters and carcass yield; however, the organic source 3,000 ppm Se-yeast results in a greater deposition of the mineral in the muscle and in a greater oxidative stability in the meat.

The poultry sector demands alternative additives to antibiotics that can be used as performance enhancers. Therefore, this experiment was conducted to evaluate the probiotics effects on performance, intestinal health and redox status of 720 broilers exposed to heat stress from 15 days of age. Eight dietary treatments were evaluated: basal diet (BD) without antibiotic and probiotic (T1); BD supplemented with antibiotic zinc bacitracin (T2), BD supplemented with commercial probiotic of Bacillus subtilis DSM 17299 (T3); BD supplemented with non-commercial probiotic of Lactococcus lactis NCDO 2118, Lactobacillus delbrueckii CNRZ 327, Escherichia coli CEC15 or Saccharomyces boulardii (T4 to T7), and BD simultaneously supplemented with the four non-commercial probiotics (T8). Feed intake, weight gain and feed conversion were determined in the period from 1 to 42 days of age. Carcass and cuts yield, abdominal fat deposition, cloacal temperature, weight and length of intestine, activity of myeloperoxidase and eosinophilic peroxidase enzymes in the jejunum, jejunal histomorphometry, relative gene expression in the jejunum (occludin, zonulin, interleukin-8, cholecystokinin, ghrelin and heat shock protein-70) and liver (heat shock protein-70), in addition to malondialdehyde level and superoxide dismutase activity in the intestine, liver and blood were measured in broilers at 42 days old. As a main results, broilers fed T1 diet exhibited lower weight gain (3.222 kg) and worse feed conversion (1.70 kg/kg). However, diets containing non-commercial probiotics resulted in up to 3.584 kg of weight gain and improved feed conversion by up to 10%, similar to that observed for broilers of the T2 and T3 groups.